Etude comparative du comportement d'organometalliques allyliques et d'organolithiens satures vis a vis de carbures: RCH≡CHC≡CR′ et RC≡CC≡CR′ (R alcoyle, R′ H, alcoyle

Summary Reactive organometallic compounds such as allyl-zinc, -magnesium and -lithium and saturated lithium compounds are shown to readily undergo addition reactions with conjugated enynes and conjugated diynes: RCH CHC≡CH and RC≡CC≡CH; this reaction is regioselective and leads to conjugated dienes, conjugated enynes or allenes. The reactivity is reduced with conjugated enynes: RCH CHC≡CR′, but organo-magnesium and -lithium compounds lead to allenes. The reaction does not take place with conjugated diynes: RC≡CC≡CR′, under normal conditions.